Apartment: great. Perfect sunsets. Overall clean, though utensils were dirty and I've had a dirty spoon in the sink when I checked-in. Also there were washed bedsheets drying on the balcony, so I just took them away a few days after. Gym is great.
Internet: fast. Never had any problem with it
Location: good. Around 15 minutes to the mall Emporium where you can find lots of shops and food, and also BTS station. Never used public transport because Bangkok is huge and wherever you stay you'll have to spend 2+ hours on commuting anyway, even by taxi. Grab was a great option -- they can pick you up near the building entrance.